Leonin Abunas is the gold standard of artifact protection. It's much better than Indomitable Archangel: hexproof instead of shroud, and doesn't require metalcraft.

Batterskull is the most powerful living weapon.

Blackblade Reforged offers a P/T boost that scales with the game and can enable Balan to one-shot.

Hammer of Nazahn provides indestructible and auto-equipping.

Inquisitor's Flail stacks with Balan's double strike.

Sword of Fire and Ice is the best Mirran Sword and is worth acquiring a copy. P/T boost, hard card draw, damage, and protections can't be beat.

Sword of the Animist is a tutorable land ramp engine.

Expedition Map tutors for one of your utility lands.

Austere Command and Cleansing Nova are excellent options for sweepers. Using artifact sweepers in an Equipment deck may seem counterproductive, but it's necessary to keep your opponents' own artifact shenanigans in check. Spot removal can only do so much against multiple players.

Remember the Fallen is a great recursion spell.

Buried Ruin is artifact recursion that only takes up a land slot.

Kor Haven is an effective threat deterrent.

Mikokoro, Center of the Sea is a cheap card draw engine.

Good suggestions, thanks! I don't have these cards right now, but I plan on acquiring all of them eventually.